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An algorithm is described for the incremental solution of elastic—plastic finite element analysis using a piecewise holonomic constitutive law based on a von Mises yield condition. The holonomic assumption effectively converts each incremental problem into a non‐linear elastic—plastic problem. The algorithm is iterative, substituting the non‐linear strain potential by a quadratic potential at each iteration, and convergence is proved. The algorithm has been implemented into a finite element program as a series of secant modulus approximations, and results for a variety of problems are given. The rate of convergence is fairly slow, but the algorithm can be very easily programmed as an extension of an elastic program, and may have value as an independent method of determining incremental elastic—plastic solutions.

Since the appearance of Simon Rottenberg's seminal paper on the baseball players' labour market in the Journal of Political Economy (1956), the literature on the economics of professional team sports has increased rapidly, fuelled by major changes in the restrictive rules which had pervaded these sports, themselves a consequence of battles in the courts and the collective bargaining arena. These changes have not been limited to North America, to which most of the literature relates, but also apply to Western Europe and Australia in particular. This monograph surveys this literature covering those various parts of the world in order to draw out both theoretical and empirical aspects. However, to argue that the existence of what is now an extensive literature “justifies” such a survey on professional team sports clearly begs a number of questions. Justification can be found in at least two major aspects.

The paper considers a plane joint or interface element suitable for implementation into a standard non‐linear finite element code. Sliding of the joint is assumed to be governed by Coulomb friction, with a non‐associated flow rule and no cohesion. The constitutive equations are formulated in a manner appropriate for a backward difference discretization in time along the path of loading. It is shown that the backward difference assumption can lead to an explicit formulation in which no essential distinction need be drawn between opening and closing of the joint and sliding when the joint is closed. However, an inherent limitation of the dilatant Coulomb model becomes evident; the final formulation is internally consistent but does not describe reversed shear displacement in a physically reasonable way. Explicit equations for the consistent tangent stiffness and for the corrector step (or return algorithm) of the standard Newton—Raphson iterative algorithm are given. The equations have been implemented as a user element in the finite element code ABAQUS, and illustrative examples are given.

The purpose of the paper is to study the stability control of permanent magnet (PM) and electromagnetic hybrid Halbach array electrodynamic suspension (EDS) system because of the poor suspension stability caused by the well-known under-damped nature of PM EDS system. The adjustment control is realized by PM and electromagnetic hybrid Halbach array, which is composed by winding active normal conductor coils on PM surface.

The three-dimensional (3-D) electromagnetic force analytical expression of PM and electromagnetic hybrid Halbach array EDS system for a nonmagnetic conductive plate is derived. And the accuracy of the derived equations is verified by a 3-D finite-element model (FEM). Basing on the 3-D levitation force expression, an acceleration feedback suspension controller is designed to suppress the vibration of PM EDS system, and the suspension stability of the system under the track and load disturbance was simulated and analyzed.

The 3-D electromagnetic force comparison of analytical model and FEM are in good agreement, which verifies the correctness of the analytical expression. The simulation results show that the acceleration feedback suspension controller can make the system have good suspension stability under the external disturbance. So it proved that the PM and electromagnetic hybrid Halbach array EDS system can overcome the poor suspension stability caused by the under-damped nature of PM EDS system through the designed acceleration feedback suspension controller.

This paper designed an acceleration feedback suspension controller to suppress the vibration of PM and electromagnetic hybrid Halbach array EDS system under external disturbance, basing on the derived levitation force analytical expression. And the simulation results show that the acceleration feedback suspension controller can make the system have good suspension stability under the external disturbance.

This issue is a selected bibliography covering the subject of leadership.

One of the principal findings of the most recent enquiry into professional football was that: “Running a successful league club is now a major commercial activity”. In general terms, professional football clubs too were confronted with financial and management problems.

Describes the life history of the British Food Journal, its changing editorial team, ownership and editorial focus. The authors have used much wider source material than the archives of the journal, now in its 100th year. The journal was always closely identified with the safety of food, its adulteration and the government’s duty to safeguard the public. The second section reviews the profession and role of the public analyst, in particular the history and development of the Society of Public Analysts. The next and longest section of the monograph is devoted to an interesting examination of food safety, nutrition and food manufacturing issues over the last 100 years. Many of the points raised are illustrated by excerpts from papers written in BFJ and included as Appendices to the monograph. Food irradiation was first raised as a subject in the journal in 1928! Bread and milk as staples in the British diet are looked at in some detail in terms of their ingredients and health properties. Some appendices have been included just for interest and provide brief snapshots of some of the main food concerns of the time, e.g. The Pure Food Society, the food we eat, food poisoning, a world food policy, the packaging of foods, food hygiene. Plus ça change ...

A 3-D analytic modeling technique for calculating the eddy current distribution, force and power loss in a conductive plate of finite width and thickness is presented. The derived equations are expressed in a general form so that any magnetic source can be utilized. The model assumes the length of the conductive plate is large and the thickness of the plate is thin but not negligible. The paper aims to discuss these issues.

The conducting and non-conducting regions are formulated in terms of decoupled magnetic vector potential components. In order to accurately compute the eddy current fields and forces the source field only needs to be applied on the surface of the conducting plate. The primary focus is on reducing the eddy current computational time.

The accuracy of the presented approach is verified by utilizing a magnetic rotor that has both a rotational and translational motion. The proposed method is computationally efficient and its accuracy is validated using the finite element method.

The conducting plate thickness is assumed to be thin (but not negligible), and this enables the field interaction through the edge of the plate to be neglected. The lateral force is not calculated in the proposed approach.

The calculation procedure presented is computationally fast and therefore this can enable the 3-D eddy current forces to be computed in near real-time.

This paper presents a fully 3-D analytic based eddy current formlation for computing the eddy current fields and forces in a conducting plate of finite thickness and finite width. The modeling approach is shown to be computationally accurate and relatively fast.

THE increasing demand for specialised rubber mouldings for advanced aircraft application in recent years has resulted in the development of a unique facility and expertise at Weybridge which is now also providing specialised elastomeric components for a wide range of industrial uses. This paper summarises progress to date.

THE OBJECTIVES of this article are twofold, firstly to argue the case for variable configuration aircraft, i.e. aircraft whose planform can be adjusted in flight to give optimum performance in differing roles; and secondly, to put forward proposals for a wing suspension designed to overcome the handicaps inherent in the method so far employed in mounting the wings of variable configuration aircraft.